The Efficacy of Hyperbaric Oxygen-assisted Treatment for ASUC and Refractory IBD

Inclusion Criteria: * According to the diagnostic criteria for ulcerative colitis in the 2018 national consensus opinion on the diagnosis and treatment of inflammatory bowel disease, it was confirmed as ulcerative colitis; * According to the Truelove-witts standard, it was diagnosed as acute severe ulcerative colitis: the frequency of bloody stools per day is 6 times or more, and at the same time, one of the following systemic toxic manifestations is present: heart rate of 90 bpm, body temperature greater than 37.8℃, hemoglobin less than 105g/L, and erythrocyte sedimentation rate greater than 30mm/h; * Age ≥ 18 years old; * Patients who can and are willing to comply with the research protocol can provide a signed and dated written informed consent form. Exclusion Criteria: * Patients who may require immediate surgical treatment; * Pregnant or lactating mothers; * Patients with a score of ≥6 years old (TMM30/40/50) and \<6 points in the measurement of the Eustachian tube; * Patients with a lung bulla larger than 2 cm at the lung apex or near the pleura in the chest plain scan; * Patients with severe liver or kidney dysfunction, heart failure or other serious systemic diseases; * Any situation that hinders the completion of the study or interferes with the analysis of the research results, including a history of drug or alcohol abuse, a smoker who has not quit, patients with mental illness or poor compliance, those with clear immune system (including HIV infection), blood system or tumor-related diseases; * Patients who have withdrawn their informed consent; * Patients who have participated in other clinical trials within 3 months before screening.